I always get confused about how the salary cap works, so I did a search for answers. This article is one of the easier to understand. It has an example of a player with a 5-year contract having various bonuses in different years, and explains exactly how much cap hit that player would generate in each year of his contract. It explains the "signing bonus", the "option bonus", the "roster bonus", guaranteed money, pro-rating a bonus, renegotiating a contract, and more.